diff --git a/pkg/vm/lib/transformations/ffi/common.dart b/pkg/vm/lib/transformations/ffi/common.dart
index 54ffd5c..42235ff 100644
--- a/pkg/vm/lib/transformations/ffi/common.dart
+++ b/pkg/vm/lib/transformations/ffi/common.dart
@@ -234,6 +234,7 @@
   final Procedure lookupFunctionTearoff;
   final Procedure getNativeFieldFunction;
   final Procedure reachabilityFenceFunction;
+  final Procedure checkAbiSpecificIntegerMappingFunction;
 
   late final InterfaceType nativeFieldWrapperClass1Type;
   late final InterfaceType voidType;
@@ -417,7 +418,9 @@
         getNativeFieldFunction = index.getTopLevelProcedure(
             'dart:nativewrappers', '_getNativeField'),
         reachabilityFenceFunction =
-            index.getTopLevelProcedure('dart:_internal', 'reachabilityFence') {
+            index.getTopLevelProcedure('dart:_internal', 'reachabilityFence'),
+        checkAbiSpecificIntegerMappingFunction = index.getTopLevelProcedure(
+            'dart:ffi', "_checkAbiSpecificIntegerMapping") {
     nativeFieldWrapperClass1Type = nativeFieldWrapperClass1Class.getThisType(
         coreTypes, Nullability.nonNullable);
     voidType = nativeTypesClasses[NativeType.kVoid]!
@@ -453,7 +456,7 @@
   /// [Bool]                               -> [bool]
   /// [Void]                               -> [void]
   /// [Pointer]<T>                         -> [Pointer]<T>
-  /// T extends [Pointer]                  -> T
+  /// T extends [Compound]                 -> T
   /// [Handle]                             -> [Object]
   /// [NativeFunction]<T1 Function(T2, T3) -> S1 Function(S2, S3)
   ///    where DartRepresentationOf(Tn) -> Sn
@@ -535,27 +538,42 @@
   InterfaceType _listOfIntType() => InterfaceType(
       listClass, Nullability.legacy, [coreTypes.intLegacyRawType]);
 
-  ConstantExpression intListConstantExpression(List<int> values) =>
+  ConstantExpression intListConstantExpression(List<int?> values) =>
       ConstantExpression(
-          ListConstant(coreTypes.intLegacyRawType,
-              [for (var v in values) IntConstant(v)]),
+          ListConstant(coreTypes.intLegacyRawType, [
+            for (var v in values)
+              if (v != null) IntConstant(v) else NullConstant()
+          ]),
           _listOfIntType());
 
   /// Expression that queries VM internals at runtime to figure out on which ABI
   /// we are.
-  Expression runtimeBranchOnLayout(Map<Abi, int> values) {
-    return InstanceInvocation(
+  Expression runtimeBranchOnLayout(Map<Abi, int?> values) {
+    final result = InstanceInvocation(
         InstanceAccessKind.Instance,
         intListConstantExpression([
-          for (final abi in Abi.values) values[abi]!,
+          for (final abi in Abi.values) values[abi],
         ]),
         listElementAt.name,
         Arguments([StaticInvocation(abiMethod, Arguments([]))]),
         interfaceTarget: listElementAt,
         functionType: Substitution.fromInterfaceType(_listOfIntType())
             .substituteType(listElementAt.getterType) as FunctionType);
+    if (values.isPartial) {
+      return checkAbiSpecificIntegerMapping(result);
+    }
+    return result;
   }
 
+  Expression checkAbiSpecificIntegerMapping(Expression nullableExpression) =>
+      StaticInvocation(
+        checkAbiSpecificIntegerMappingFunction,
+        Arguments(
+          [nullableExpression],
+          types: [InterfaceType(intClass, Nullability.nonNullable)],
+        ),
+      );
+
   /// Generates an expression that returns a new `Pointer<dartType>` offset
   /// by [offset] from [pointer].
   ///
@@ -819,3 +837,8 @@
   }
   return false;
 }
+
+extension on Map<Abi, Object?> {
+  bool get isPartial =>
+      [for (final abi in Abi.values) this[abi]].contains(null);
+}
diff --git a/pkg/vm/lib/transformations/ffi/definitions.dart b/pkg/vm/lib/transformations/ffi/definitions.dart
index d80ef22..fbf2052 100644
--- a/pkg/vm/lib/transformations/ffi/definitions.dart
+++ b/pkg/vm/lib/transformations/ffi/definitions.dart
@@ -448,9 +448,8 @@
         // This class is invalid, but continue reporting other errors on it.
         success = false;
       } else {
-        final DartType nativeType = InterfaceType(
-            nativeTypesClasses[_getFieldType(nativeTypeAnnos.first)!]!,
-            Nullability.legacy);
+        final DartType nativeType =
+            InterfaceType(nativeTypeAnnos.first, Nullability.legacy);
         final DartType? shouldBeDartType = convertNativeTypeToDartType(
             nativeType,
             allowCompounds: true,
@@ -704,7 +703,6 @@
 
   static const vmFfiStructFields = "vm:ffi:struct-fields";
 
-  // return value is nullable.
   InstanceConstant? _compoundAnnotatedFields(Class node) {
     for (final annotation in node.annotations) {
       if (annotation is ConstantExpression) {
@@ -774,7 +772,6 @@
     return UnionNativeTypeCfe(compoundClass, members);
   }
 
-  // packing is `int?`.
   void _annoteCompoundWithFields(
       Class node, List<NativeTypeCfe> types, int? packing) {
     List<Constant> constants =
@@ -794,8 +791,13 @@
         InterfaceType(pragmaClass, Nullability.nonNullable, [])));
   }
 
-  void _generateMethodsForField(Class node, Field field, NativeTypeCfe type,
-      Map<Abi, int> offsets, bool unalignedAccess, IndexedClass? indexedClass) {
+  void _generateMethodsForField(
+      Class node,
+      Field field,
+      NativeTypeCfe type,
+      Map<Abi, int?> offsets,
+      bool unalignedAccess,
+      IndexedClass? indexedClass) {
     // TODO(johnniwinther): Avoid passing [indexedClass]. When compiling
     // incrementally, [field] should already carry the references from
     // [indexedClass].
@@ -846,7 +848,7 @@
   /// If sizes are not supplied still emits a field so that the use site
   /// transformer can still rewrite to it.
   void _addSizeOfField(Class compound, IndexedClass? indexedClass,
-      [Map<Abi, int>? sizes = null]) {
+      [Map<Abi, int?>? sizes = null]) {
     if (sizes == null) {
       sizes = {for (var abi in Abi.values) abi: 0};
     }
diff --git a/pkg/vm/lib/transformations/ffi/native_type_cfe.dart b/pkg/vm/lib/transformations/ffi/native_type_cfe.dart
index 9784ac9..862d1bd 100644
--- a/pkg/vm/lib/transformations/ffi/native_type_cfe.dart
+++ b/pkg/vm/lib/transformations/ffi/native_type_cfe.dart
@@ -52,12 +52,12 @@
   }
 
   /// The size in bytes per [Abi].
-  Map<Abi, int> get size;
+  Map<Abi, int?> get size;
 
   /// The alignment inside structs in bytes per [Abi].
   ///
   /// This is not the alignment on stack, this is only calculated in the VM.
-  Map<Abi, int> get alignment;
+  Map<Abi, int?> get alignment;
 
   /// Generates a Constant representing the type which is consumed by the VM.
   ///
@@ -70,7 +70,7 @@
   ///
   /// Takes [transformer] to be able to lookup classes and methods.
   ReturnStatement generateGetterStatement(DartType dartType, int fileOffset,
-      Map<Abi, int> offsets, bool unalignedAccess, FfiTransformer transformer);
+      Map<Abi, int?> offsets, bool unalignedAccess, FfiTransformer transformer);
 
   /// Generates the return statement for a compound field setter with this type.
   ///
@@ -78,7 +78,7 @@
   ReturnStatement generateSetterStatement(
       DartType dartType,
       int fileOffset,
-      Map<Abi, int> offsets,
+      Map<Abi, int?> offsets,
       bool unalignedAccess,
       VariableDeclaration argument,
       FfiTransformer transformer);
@@ -90,7 +90,7 @@
   InvalidNativeTypeCfe(this.reason);
 
   @override
-  Map<Abi, int> get alignment => throw reason;
+  Map<Abi, int?> get alignment => throw reason;
 
   @override
   Constant generateConstant(FfiTransformer transformer) => throw reason;
@@ -99,7 +99,7 @@
   ReturnStatement generateGetterStatement(
           DartType dartType,
           int fileOffset,
-          Map<Abi, int> offsets,
+          Map<Abi, int?> offsets,
           bool unalignedAccess,
           FfiTransformer transformer) =>
       throw reason;
@@ -108,14 +108,14 @@
   ReturnStatement generateSetterStatement(
           DartType dartType,
           int fileOffset,
-          Map<Abi, int> offsets,
+          Map<Abi, int?> offsets,
           bool unalignedAccess,
           VariableDeclaration argument,
           FfiTransformer transformer) =>
       throw reason;
 
   @override
-  Map<Abi, int> get size => throw reason;
+  Map<Abi, int?> get size => throw reason;
 }
 
 class PrimitiveNativeTypeCfe implements NativeTypeCfe {
@@ -126,7 +126,7 @@
   PrimitiveNativeTypeCfe(this.nativeType, this.clazz);
 
   @override
-  Map<Abi, int> get size {
+  Map<Abi, int?> get size {
     final int size = nativeTypeSizes[nativeType]!;
     if (size == WORD_SIZE) {
       return wordSize;
@@ -147,7 +147,7 @@
   bool get isFloat =>
       nativeType == NativeType.kFloat || nativeType == NativeType.kDouble;
 
-  bool isUnaligned(Map<Abi, int> offsets) {
+  bool isUnaligned(Map<Abi, int?> offsets) {
     final alignments = alignment;
     for (final abi in offsets.keys) {
       final offset = offsets[abi]!;
@@ -168,7 +168,7 @@
   ReturnStatement generateGetterStatement(
           DartType dartType,
           int fileOffset,
-          Map<Abi, int> offsets,
+          Map<Abi, int?> offsets,
           bool unalignedAccess,
           FfiTransformer transformer) =>
       ReturnStatement(StaticInvocation(
@@ -191,7 +191,7 @@
   ReturnStatement generateSetterStatement(
           DartType dartType,
           int fileOffset,
-          Map<Abi, int> offsets,
+          Map<Abi, int?> offsets,
           bool unalignedAccess,
           VariableDeclaration argument,
           FfiTransformer transformer) =>
@@ -210,10 +210,10 @@
 
 class PointerNativeTypeCfe implements NativeTypeCfe {
   @override
-  Map<Abi, int> get size => wordSize;
+  Map<Abi, int?> get size => wordSize;
 
   @override
-  Map<Abi, int> get alignment => wordSize;
+  Map<Abi, int?> get alignment => wordSize;
 
   @override
   Constant generateConstant(FfiTransformer transformer) => TypeLiteralConstant(
@@ -231,7 +231,7 @@
   ReturnStatement generateGetterStatement(
           DartType dartType,
           int fileOffset,
-          Map<Abi, int> offsets,
+          Map<Abi, int?> offsets,
           bool unalignedAccess,
           FfiTransformer transformer) =>
       ReturnStatement(StaticInvocation(
@@ -259,7 +259,7 @@
   ReturnStatement generateSetterStatement(
           DartType dartType,
           int fileOffset,
-          Map<Abi, int> offsets,
+          Map<Abi, int?> offsets,
           bool unalignedAccess,
           VariableDeclaration argument,
           FfiTransformer transformer) =>
@@ -281,15 +281,15 @@
 /// The layout of a `Struct` or `Union` in one [Abi].
 class CompoundLayout {
   /// Size of the entire struct or union.
-  final int size;
+  final int? size;
 
   /// Alignment of struct or union when nested in a struct.
-  final int alignment;
+  final int? alignment;
 
   /// Offset in bytes for each field, indexed by field number.
   ///
   /// Always 0 for unions.
-  final List<int> offsets;
+  final List<int?> offsets;
 
   CompoundLayout(this.size, this.alignment, this.offsets);
 }
@@ -304,11 +304,11 @@
   CompoundNativeTypeCfe._(this.clazz, this.members, this.layout);
 
   @override
-  Map<Abi, int> get size =>
+  Map<Abi, int?> get size =>
       layout.map((abi, layout) => MapEntry(abi, layout.size));
 
   @override
-  Map<Abi, int> get alignment =>
+  Map<Abi, int?> get alignment =>
       layout.map((abi, layout) => MapEntry(abi, layout.alignment));
 
   @override
@@ -323,8 +323,12 @@
   /// );
   /// ```
   @override
-  ReturnStatement generateGetterStatement(DartType dartType, int fileOffset,
-      Map<Abi, int> offsets, bool unalignedAccess, FfiTransformer transformer) {
+  ReturnStatement generateGetterStatement(
+      DartType dartType,
+      int fileOffset,
+      Map<Abi, int?> offsets,
+      bool unalignedAccess,
+      FfiTransformer transformer) {
     final constructor = clazz.constructors
         .firstWhere((c) => c.name == Name("#fromTypedDataBase"));
 
@@ -351,7 +355,7 @@
   ReturnStatement generateSetterStatement(
           DartType dartType,
           int fileOffset,
-          Map<Abi, int> offsets,
+          Map<Abi, int?> offsets,
           bool unalignedAccess,
           VariableDeclaration argument,
           FfiTransformer transformer) =>
@@ -389,23 +393,23 @@
   // NativeStructType::FromNativeTypes.
   static CompoundLayout _calculateLayout(
       List<NativeTypeCfe> types, int? packing, Abi abi) {
-    int offset = 0;
-    final offsets = <int>[];
-    int structAlignment = 1;
+    int? offset = 0;
+    final offsets = <int?>[];
+    int? structAlignment = 1;
     for (int i = 0; i < types.length; i++) {
-      final int size = types[i].size[abi]!;
-      int alignment = types[i].alignment[abi]!;
-      if (packing != null && packing < alignment) {
-        alignment = packing;
+      final int? size = types[i].size[abi];
+      int? alignment = types[i].alignment[abi];
+      if (packing != null) {
+        alignment = min(packing, alignment);
       }
-      if (alignment > 0) {
-        offset = _alignOffset(offset, alignment);
+      if (alignment != null && alignment > 0) {
+        offset = offset.align(alignment);
       }
       offsets.add(offset);
       offset += size;
-      structAlignment = math.max(structAlignment, alignment);
+      structAlignment = max(structAlignment, alignment);
     }
-    final int size = _alignOffset(offset, structAlignment);
+    final int? size = offset.align(structAlignment);
     return CompoundLayout(size, structAlignment, offsets);
   }
 }
@@ -425,15 +429,15 @@
   // Keep consistent with runtime/vm/compiler/ffi/native_type.cc
   // NativeUnionType::FromNativeTypes.
   static CompoundLayout _calculateLayout(List<NativeTypeCfe> types, Abi abi) {
-    int unionSize = 1;
-    int unionAlignment = 1;
+    int? unionSize = 1;
+    int? unionAlignment = 1;
     for (int i = 0; i < types.length; i++) {
-      final int size = types[i].size[abi]!;
-      int alignment = types[i].alignment[abi]!;
-      unionSize = math.max(unionSize, size);
-      unionAlignment = math.max(unionAlignment, alignment);
+      final int? size = types[i].size[abi];
+      int? alignment = types[i].alignment[abi];
+      unionSize = max(unionSize, size);
+      unionAlignment = max(unionAlignment, alignment);
     }
-    final int size = _alignOffset(unionSize, unionAlignment);
+    final int? size = unionSize.align(unionAlignment);
     return CompoundLayout(size, unionAlignment, List.filled(types.length, 0));
   }
 }
@@ -476,11 +480,11 @@
   }
 
   @override
-  Map<Abi, int> get size =>
+  Map<Abi, int?> get size =>
       elementType.size.map((abi, size) => MapEntry(abi, size * length));
 
   @override
-  Map<Abi, int> get alignment => elementType.alignment;
+  Map<Abi, int?> get alignment => elementType.alignment;
 
   // Note that we flatten multi dimensional arrays.
   @override
@@ -500,8 +504,12 @@
   /// );
   /// ```
   @override
-  ReturnStatement generateGetterStatement(DartType dartType, int fileOffset,
-      Map<Abi, int> offsets, bool unalignedAccess, FfiTransformer transformer) {
+  ReturnStatement generateGetterStatement(
+      DartType dartType,
+      int fileOffset,
+      Map<Abi, int?> offsets,
+      bool unalignedAccess,
+      FfiTransformer transformer) {
     InterfaceType typeArgument =
         (dartType as InterfaceType).typeArguments.single as InterfaceType;
     return ReturnStatement(ConstructorInvocation(
@@ -531,7 +539,7 @@
   ReturnStatement generateSetterStatement(
           DartType dartType,
           int fileOffset,
-          Map<Abi, int> offsets,
+          Map<Abi, int?> offsets,
           bool unalignedAccess,
           VariableDeclaration argument,
           FfiTransformer transformer) =>
@@ -549,5 +557,71 @@
         ..fileOffset = fileOffset);
 }
 
-int _alignOffset(int offset, int alignment) =>
-    ((offset + alignment - 1) ~/ alignment) * alignment;
+extension on int? {
+  int? align(int? alignment) =>
+      ((this + alignment - 1) ~/ alignment) * alignment;
+
+  int? operator *(int? other) {
+    final this_ = this;
+    if (this_ == null) {
+      return null;
+    }
+    if (other == null) {
+      return null;
+    }
+    return this_ * other;
+  }
+
+  int? operator +(int? other) {
+    final this_ = this;
+    if (this_ == null) {
+      return null;
+    }
+    if (other == null) {
+      return null;
+    }
+    return this_ + other;
+  }
+
+  int? operator -(int? other) {
+    final this_ = this;
+    if (this_ == null) {
+      return null;
+    }
+    if (other == null) {
+      return null;
+    }
+    return this_ - other;
+  }
+
+  int? operator ~/(int? other) {
+    final this_ = this;
+    if (this_ == null) {
+      return null;
+    }
+    if (other == null) {
+      return null;
+    }
+    return this_ ~/ other;
+  }
+}
+
+int? max(int? a, int? b) {
+  if (a == null) {
+    return null;
+  }
+  if (b == null) {
+    return null;
+  }
+  return math.max(a, b);
+}
+
+int? min(int? a, int? b) {
+  if (a == null) {
+    return null;
+  }
+  if (b == null) {
+    return null;
+  }
+  return math.min(a, b);
+}
diff --git a/sdk/lib/_internal/vm/lib/ffi_patch.dart b/sdk/lib/_internal/vm/lib/ffi_patch.dart
index 14180b6..3af29c3 100644
--- a/sdk/lib/_internal/vm/lib/ffi_patch.dart
+++ b/sdk/lib/_internal/vm/lib/ffi_patch.dart
@@ -448,6 +448,16 @@
         Pointer<Pointer<S>> pointer, int index) =>
     Pointer.fromAddress(pointer.address + _intPtrSize * index);
 
+@pragma("vm:prefer-inline")
+@pragma("vm:entry-point")
+T _checkAbiSpecificIntegerMapping<T>(T? object) {
+  if (object == null) {
+    throw ArgumentError(
+        'AbiSpecificInteger is missing mapping for "${Abi.current()}".');
+  }
+  return object;
+}
+
 extension NativeFunctionPointer<NF extends Function>
     on Pointer<NativeFunction<NF>> {
   @patch